Hashtags

On platforms supporting hashtags, broadcasting or following the following should turn up other Google+ refugees:

#googleplus #gplusrefugees #gplusrefugee #gplusexodus

Sites & Platforms

LifeCloud

LifeCloud has a community aspect similar to G+ and is the only platform to offer a public import tool allowing you to quickly import and recreate all your Google+ communities, collections, and posts in minutes.

Cake

The Cake interest category "Google+" has 136 followers as of 31 January 2019.

Diaspora

Does not support groups or communities.

The Pluspora pod is operated and principally populated by Google+ refugees with over 7,900 members as of 15 December 2018

Minds

Reddit

There are several Google+ and specifically Google+ Refugee subreddits.

/r/GooglePlus: a general-interest Google Plus forum not specifically oriented at refugees. Moderators have not responded to inquiries from Dredmorbius (/u/dredmorbius at Reddit). 6,718 subscribers as of 29 January 2019.